My rule of thumb is this.
When you are considering promoting yourself with Social Media, Use the 75 – 25 approach.
75% of the time you should spend building your following on social media. The more followers you have the more you will get exposure for your work. If you are constantly just promoting yourself and trying to sell your work people will tune out and disengage.
Put more time into engaging with people and not just trying to sell to them.
Once you have engaged with them then let them know casually that you have work to offer…. 25%